High barium content complex salts of sulfonic acids and method for preparing same



United States Patent M HIGH B CONTENT COWLEX SALTS OF SULFONIC ACIDS AND METHOD FOR PREPAR- ING SAME Harry J. Andress, In, Pittman, N.J., assignor to Socony Mobil Oil Company, Inc, a corporation of New York No Drawing. Original application June It), 1957, Ser. No. 664,465, now Patent No. 3,946,224, dated July 24, 1962. Divided and this application May 14, 1959, Ser. No. 813,070

8 Claims. (Cl. 25233) This invention is directed to a new class of high barium content complex salts of sulfonic acids and to a method for preparing these salts. The invention also contemplates the use of these salts as addition agents for various mineral oil fractions, particularly mineral lubricating oils.

It is well known that lubricating oils tend to deteriorate under the conditions of use in present day diesel and automotive engines with attendant formation of sludge, lacquer and resinous materials which adhere to the engine parts, particularly the piston ring grooves and skirts, thereby lowering the operating efficiency of the engine. To counteract the formation of these deposits, certain chemical additives have been found which when added to lubricating oils have the ability to keep the depositforming materials suspended in the oil, so that the engine is kept clean and in efficient operating condition for extended periods of time. These addition agents are known in the art as detergents or dispersants. Metal organic compounds are particularly useful in this respect. These metal organic compounds are considered to be effective on the basis of their metal contents, coupled with their solubility in the oil.

Generally, it has been found that the oil-soluble metal organic compounds having the greatest percentages of metal provide the better detergents. On this basis, it has been sought to provide detergent compounds having the highest possible metal content. Metal sulfonates, particularly barium sulfonates derived from sulfonic acids, such as are obtained by the sulfonation of petroleum oils, or synthetic sulfonic acids obtained by the sulfonation of alkyl aryl compounds, such as alkyl-substituted benzenes and naphthalenes, are recognized in the art as being particularly elfective detergents for mineral lubricating oils. The art has sought, therefore, to still further enhance the elfectiveness of these compounds by increasing their barium contents.

The present invention is concerned with the provision of a new class of barium sulfonates, hereinafter called complex barium sulfonates, which have exceptionally high metal contents and which are highly superior oil detergents. They are also effective as anti-sludging and anti-screen clogging agents in fuel oils. The metal contents of these new complex salts range from at least about 200% to at least 1300% higher than those of the corresponding normal barium salts, i.e., salts having barium contents equivalent to the acid-hydrogen contents of the respective sulfonic acids from whichth ey are derived.

It is the primary object of this invention to provide a new class of complex barium sulfonate salts having exceptionally high barium contents and also a method for preparing these salts.

It is a further object to provide oil compositions containing relatively small amounts of these salts, which compositions are of high detergent character.

It is a further object to provide fuel oil compositions containing these complex salts, said compositions having improved anti-sludging and anti-clogging characteristics.

Other and further objects will become apparent from the following description of the invention.

As is well known, sulfonic acid may be reacted with barium hydroxide to produce either (a) neutral (normal) salts thereof conforming to the general formula' SO BaSO (R) :wO (R) n wherein R represents alkyl, aryl or alkaryl groups and n is an integer from 1 to 5; or (b) basic salts, conforming to the general formula SO BaOH alent) of the acid with 1 mol (2 equivalents) of barium hydroxide. Salts having high barium contents, however, are not produceable by thesimple neutralization of a sulfonic acid with barium hydroxide, although, as afore-indicated, the obtainment of higher barium content sulfonate salts is a highly desirable objective from the stand-point of the application of such salts as lubricating oil detergents.

The present invention provides a means for producing barium salts of sulfonic acids having barium contents ranging from 3 to as high as 14, or more, equivalents of barium per equivalent of acid-hydrogen content in the sulfonic acids from whichthey are derived. These new salts, therefore, have barium contents which are up to 14 times as high as the barium contents of the neutral or normal barium sulfonate salts and 7 times as high as the known basic barium salts. Also, the new salts have base numbers several times greater than the basic barium salts (Formula II). This high degree of alkalinity is a pronounced advantage when the salts are employed in engines using high sulfur fuels.

In accordance with this invention, it has been found that the basic barium salts of sulfonic acids (Formula II) can be reacted with carbon dioxide and barium methylate (BaOH(OCH to provide these new high barium content complex barium salts. The normal barium sulfonate salts (Formula I), on the other hand, do not lend themselves to the process of the invention, the high barium content complex salts not being obtained when the normal salts are employed as starting materials in the process.

In general, the procedure for preparing the high barium content complex salts in accordance with the invention is as follows. An oil solution of the basic barium sulfonate salt is charged to a reaction vessel having means for introduction and dispersion of carbon dioxide. The oil solution is heated and maintained at a temperature of from about C. to about 250 C., while carbon dioxide is passed therethrough. The carbonation treatment is continued for a time sutficient to effect reaction of about 1 mol of carbon dioxide per mol of basic barium salt present in the oil solution. The amount of carbon dioxide employed during the carbonation, therefore, should be at least about 1 mol per mol of basic barium sulfonate salt in the oil solution and preferably a substantial excess of carbon dioxide over this amount, say, at least 2 mols or more should be used. It has been found that the use of excess carbon dioxide is necessary when the carbonation is conducted by blowing or bubbling the gas through the oil solution at atmospheric pressure as under these conditions the utilization of the carbon dioxide is not very efficient. In carrying out the carbonation under these latter conditions, the time required may vary between Patented Nov, 24, 1964 about 1 hour and about hours, depending upon the rate of admission of the carbon dioxide and the efficiency of contacting obtained. From a practical standpoint, it is, of course, desirable to effect the: carbonation in as short a time as possible. As will be apparent to those skilled in the art, the carbonation time can be substantially reduced by the use of special equipment, such as pressure reactors, etc., designed to enhance the efliciency of the reaction. Accordingly, it is considered that any and all such modifications of the carbonation procedure are within the scope of this invention.

When the carbonation step has been completed, the reaction mixture is cooled to a temperature below the boiling point of methyl alcohol, say, from about 25 C. to about 60 C., and barium methylate solution is added in sufficient amount to provide at least 1 equivalent of barium, based on the acid-hydrogen content of the sulfonic acid from which the basic barium sulfonate salt was prepared. Expressed differently, this means that at least about 1 equivalent of barium is added per mol of basic barium sultonate in the oil solution. The reaction mixture is again heated to a temperature of 150 C. to 250 C. and maintained at this temperature for a short time, say, hour, to provide complete removal of uncombined methanol. The reaction mixture is then filtered (preferably while heated) to provide an oil solution of the complex salt product containing approximately 3 equivalents of barium. The complex salt product thus obtained may be subjected to further carbonation and barium methylate treatments to provide a product salt of still higher barium content, each successive repetition of these treating steps adding 1 equivalent of barium to the complex salt product. In these subsequent treatments, the carbon dioxide is apparently incorporated in amounts up to /2 mol per mol of basic barium salt employed in the process, the ratio of added carbon dioxide to added barium being about 1:1. Each repetition of the carbonation treatment, therefore, involves the utilization of the carbon dioxide in amounts up to about /2 mol, the amount of barium incorporated by each subsequent barium methylate treatment being related to the amount of carbon dioxide reacted in each carbonation treatment. As will be ob served from the examples given herein, complex salts having as many as 14 equivalents (7 mols) of barium per equivalent of sulfonic acid content therein have been successfully prepared. Greater amounts of barium can be introduced into these salts by further application of carbonation and barium methylate treatments.

The exact manner in which the carbon dioxide and barium methylate interact with the basic barium salts or provide the complexed carbonated sulfonate salt of the inven tion is not known and the product salts are, therefore, defined herein by their method of preparation. It has been found, however, that all of the product salts release carbon dioxide when treated with mineral acid. Also, all of the products have been found to contain small but significant amounts of methylate groups. Analyses of the products have shown them to contain carbon dioxide and barium in approximately equimolar proportions. Thus, for example, the product of Example 6, presented hereinafter, which was prepared by repeated carbonation and barium methylate treatments analyzed 31.5% barium, 9.0% carbon dioxide and 0.3% methylate groups. It will be seen that the mol ratio of barium to carbon dioxide in this product is approximately 1:1. Without intending to limit the invention bytheoretical consideratons, therefore, it is believed that the reactions which occur when a basic barium sulfonate salt is subjected to the process of the invention may be somewhat as repre sented in the following series of equations (R=alkyl): (I)

(II) 0 OH ll S0;Ba0 011+ Ba 2R oorra p soanaodo R 00H,

OH sO BaOgO l 0 (III) H SO BaOCO R con,

Ba CO3 ---v SO Ba0CO R :1

' i soauaodo R 00H,

on on SO BaO0 o R 0 Ba. Ba

ogorr OCH:

0 sosnaoc o R o o so eaoiio R o 0on3 Ba\ /Ba GE30H ofio on 0 5031321000 R 11 t /OCH3 4 Ba\ /-Ba\ +00:

/ CKHJO on i SOaBaOC O It will be appreciated that additional application of he carbonation and barium methylate treating steps will produce products having additional groups therein. Thus, the general equation for the reactions which occur in the process may be represented as The sulfonic acids suitable for use in the invention include oil soluble petroleum sulionic acids and synthetic alkaryl sulfonic acids, particularly those having higher molecular weights, i.e., from about 300 to about 800. These sulfonic acids may be produced by 'sulfonation of petroleum stocks or synthetic allryl aromatic compounds, such as alkyd-substituted benzenes or naphthalenes wherein the alkyl groups attached to the aromatic ring contain from at least about 8 to about 24, or more, carbon atoms. Specific synthetic sulfonic acids are, for example, octyl benzene sulfouic acid, dodecyl benzene sulfonic acid, dioctyl benzene sulfonic acid, octadecyl benzene sulfonic acid, wax benzene sulfonic acid and wax naphthalene sulfonic acid. Of the various acids the wax benzene and wax naphthalene sulfonic acids are particularly preferred.

The petroleum sulfonic acids, also known as sour oils, are those obtained in the treatment of petroleum oils, particularly refined, or semi-refined oils, with concentrated or fuming sulfuric acid, and which remain in the oil after settling out of sludge.

It will be appreciated that the basic barium sulfonate salts utilized as starting materials in the invention, as ordinarily prepared, are actually oil solutions. Thus, the petroleum sulfonate salts are preparedfrom petroleum sulfonic acids, i.e,., sour oils, containing from about 25% to about 75%, by weight, of oil, by reaction with barium hydroxide. Also, the synthetic sulfonic acids are ordinarily prepared with the use of a diluent oil to provide products which are oil solutions, said solutions also containing from about 25% to about 75%, by Weight, of oil (see Product A below). The presence of the oil is advantageous in the process of the invention since it facilitat-es the conducting of the carbonation and barium methylate reaction steps as well as the filtration and handling of the final products. However, it is contemplated that other hydrocarbon diluents besides mineral lubri ating oil may be employed. Thus, solvent hydrocarbons, such as light naphthas, xylene, toluene and the like may be utilized in the process either alone (in the case of the synthetic sulfonates) or in conjunction with the oil already present in the acid (as in the case of the petroleum sulfonates). The use of mineral oil, however, is preferred since it need not be removed from the product salts, the product oil solutions being directly blendable with lubricating or fuel oils desired to be improved therewith.

The method of the invention is illustrated in detail in Examples 1 to 6 presented herebelow. The barium sulfonate salt utilized as the starting material in each of these examples was a basic barium salt or" a wax-substituted-benzene sulfouic acid prepared as shown in Example A. The barium methylate reagent was prepared in the well known manner by reaction of barium oxide with methyl alcohol according to the equation,

13210 CH OH+B a.OH(OCH Example A rine gas until the weight of the wax had increased about i 12%. The chlorowax thus obtained was then blown with nitrogen to remove any occluded chlorine and hydrogen chloride.

A IOOO-gram portion of the chlorowax was then mixed with 500 grams of benzene in a 3-necked flask equipped with a stirrer, reflux condenser and a thermometer. The mixture was heated to a temperature of 60 C. Aluminum chloride was then added slowly'over a period of 2 hours. The addition of the aluminum chloride was accompanied by a vigorous evolution of hydrogen chloride. The temperature was then raised to about C. and h ld there for 1 hour. The excess benzene was then removed by inverting the refiux condenser and heating to a temperature of 116 C. Two hundred milliliters of benzene were recovered. The mixture was cooled to 60 C. and then another 1000 grams of chlorowax were added slowly. The temperature was then raised to C. and held there for 1 hour. The product was allowed to stand overnight at a temperature of 60 C. and then was sepa- I'Tlfid from the sludge by decantation and filtered through c ay.

I Seventeen hundred and thirty-eight grams of wax-benzene thus obtained were placed in a S-necked flask and heated to 40 C. Eight hundred and sixty-nine grams of oleum (15% S0 Wereaddedslowly to the wax-benzene at a rate regulated to maintain the temperature below 50 C. The addition of oleum consumed about 3 hours. The mixture was then stirred for an additional hour to insure complete reaction. The mixture was then 'in the reaction and are useful in the invention.

poured into 1000 milliliters of water and subsequently 1810 grams of mineral oil were added to the mixture. The mixture was thoroughly stirred and then allowed to stand until the water separated into a layer. The water layer was drained 01f. The product thus obtained was approximately a 50% blend of wax-benzene sulfonic acid (2-12) in mineral oil and had a neutralization number of 42.

(11) Preparation of the Basic Barium Salt of Wax- Benzene (2-12) Sulfonic Acid: Five hundred grams of wax-benzene (2-12) sulfonic acid prepared above were charged to a 2 liter, 4-necked, round-bottomed flask equipped with a mechanical stirrer and thermometer. Two equivalents (118.3 grams) of barium hydroxide octahydrate were added to the mixture and the temperature of the mixture was slowly raised to about 150 C. and held for 1 hour. The mixture was then filtered through a layer of Hyfio (a diatomaceous clay filter-aid). The product thus obtained, Product A, the basic barium salt of wax-benzene sulfonate (2-12), analyzed about by weight, of barium. It was diluted with mineral oil to provide a final oil solution containing 7.5% barium.

It will be understood that a wax-benzene prepared according to the foregoing procedure in which a quantity of chlo-rowax containing 2 atomic proportions of chlorine and having a chlorine content of 12% is reacted with 1 mol of benzene is designated wax-benzene (212). Similarly, wax-benzene (3-10) and wax-benzene (1- 10) may also be prepared by the reaction of sufiicient amounts of chlorinated wax, containing 10%, by weight, of chlorine, to provide 3 atomic proportions and 1 atomic proportion of chlorine per mol of benzene, respectively,

In general, the amount of chlorowax containing from about 10% to about 18%, by weight, of chlorine used in the reaction is sufiicient to supply between 1 and 4 atomic proportions of chlorine per mol of benzene used.

Example 1 Nine hundred and fifty-eight grams of Product A (7.5% barium) was blown with carbon dioxide for 3 hours at 200 C. The reaction mixture was cooled to 60 C. and 34.5 grams of barium (1 equivalent based on the acid number of the wax-benzene sulfonic acid of Product A corrected for final oil dilution of the product) in the form of a barium methylate solution in methanol was added. The mixture was then heated to 175 C. and filtered through Hyfio clay. The product analyzed 10.13% barium in the oil blend which approximated the theoretical barium for a complex barium salt of waxbenzene (2-12) sulfonic acid containing 3 equivalents of barium.

Example Fourteen hundred grams of Product A (7.5% barium) was blown with carbon dioxide for 3 hours at 200 C. The reaction mixture was cooled to 60 C. and 50.4 grams of barium (1 equivalent based on the acid number of the oil blend of the wax-benzene sulfonic acid intermediate of Product A corrected for final oil dilution of the product) in the form of a barium methylate solution in methanol was added. The mixture was heated to 200 C. and again blown with carbon dioxide for 4 hours at 200 C. The reaction mixture was then cooled to 60 C. and 50.4 grams of barium, as barium methylate, was added. The mixture was heated to 175 C. and filtered through Hyflo clay. The product analyzed 13.15% barium in the oil blend which approximated the theoretical barium for a complex barium salt of waxbenzene (2-12) sulfonic acid containing 4 equivalents of barium.

Example 3 Seven hundred and twenty grams of a complex barium wax-benzene (2-12) salt containing 3 equivalents of barium (10.25% barium) made according to Example 1 was blown with carbon dioxide for 4 hours at 200 C. The reaction mixture was cooled to 60 C. and 27 grams of barium (1 equivalent based on the acid number of the oil blend of the wax-benzene sulfonic acid intermediate of Product A corrected for final oil dilution of the product) in the form of a barium methylate solution in methanol was added. The mixture was heated at 200 C. and blown with carbon dioxide for 4 hours at 200 C. The reaction mixture was then cooled to 60 C. and 27 grams of barium (see above) was added. The mixture was heated to C. and filtered through a layer of Hyfio clay. The product analyzed 16.3% barium in the oil blend which approximated the theoretical barium for a complex salt of a wax-benzene (2-12) sulfonic acid containing 5 equivalents of barium.

Example 4 Seven hundred and twenty grams of a complex barium wax-benzene (2-12) salt containing 3 equivalents of barium (10.25% barium) made according to Example 1 was blown with carbon dioxide for 4 hours at 200 C. The reaction mixture was cooled to 60 C. and 27 grams of barium (1 equivalent) based on the acid number of the oil blend of the wax-benzene sulfonic acid intermediate of Product A corrected for final oil dilution of the product) in the form of a barium methylate solution in methanol was added. The mixture was heated to 200 C. and blown with carbon dioxide for 4 hours at 200 C. The mixture was then cooled to 60 C. and 27 grams of barium, as barium methylate, (see above) was added. The reaction mixture was then heated to 200 C. and blown with carbon dioxide for 4 hours at 200 C. The mixture was then cooled to 60 C. and 27 grams of barium as barium methylate, (see above) was added. The reaction mixture was heated to 175 C. and filtered through a layer of Hyflo clay. The product analyzed 18.31% barium in the oil blend which approximated the theoretical barium for a barium salt of wax-benzene sulfonic acid containing 6 equivalents of barium.

Example 5 Nine hundred and seventy-nine grams of the product of Example 2-a complex barium salt containing 4 equivalents of barium (13.15% barium)--was blown with carbon dioxide for 3 hours at 200 C. The reaction mixture was cooled to 60 C. and 35 grams of barium (1 equivalent based on the acid number of the oil blend of the wax-benzene sulfonic acid intermediate of Product A corrected for final oil dilution of the product) in the form of barium methylate solution in methanol was added. The mixture was heated to 200 C. and blown with carbon dioxide for 3 hours at 200 C. The reaction mixture was then cooled to 60 C. and 35 grams of barium, as barium methylate, (see above) was added. The mixture was heated to 200 C. and blown with carbon dioxide for 3 hours at 200 C. The reaction mixture was then cooled to 60 C. and 35 grams of barium, as barium methylate, (see above) was added. The mixture was heated to 175 C. and filtered through a layer of Hyflo clay. The product analyzed 20.6% barium which approximated the theoretical barium for a complex barium salt of a wax-benzene (2-12) sulfonic acid containing 7 equivalents of barium.

Example 6 Fourteen hundred grams of Product A (7.5 barium) Was blown with carbon dioxide for 3 hours at 200 C. The reaction mixture was cooled to 60 C. and 52.5 grams of barium (1 equivalent based on the acid number of the oil blend of the wax-benzene sulfonic acid intermediate of Product A corrected for final oil dilution of said product) in the form of a barium methylate solution in methanol was added. The reaction mixture was heated to 200 C. The above carbon dioxide and barium methylate treatments were each repeated 11 additional times. The final product obtained after filtration through a layer of l-lyflo clay analyzed 31.5% barium. It also contain d 9.03% carbon dioxide and 0.3% methylate radicals and had a total Base Number of 262. The barium content approximated the theoretical barium for a complex barium salt of wax-benzene sulionic acid containing 14 equivalents of barium.

EVALUATION OF COMPLEX SALTS AS LUBRICATING OIL ADDITlV ES The ability of the high barium content complex sulfonate salts of the invention as detergents in lubricating oil has been shown by a number of comparative tests conducted on the base lubricating oils alone and on these same oils blended with minor amounts or representative product salts described in the preceding examples. The tests used were the Lauson D- lA Detergency Test, the CPR Diesel Detergency Test, D2l, and the Caterpillar Engine Test. The results of the various tests are presented in Tables I, II and 111, respectively. The complex salts of the invention were also subjected to the Radioactive Piston Ring Wear Test in order to show their ability in preventing piston ring wear. The results obtained in these tests are given in Table IV. The several test procedures were as follows:

LAUSON DETERGENCY TEST D-4A This test determines the effectiveness of the lubricating oil in preventing fouling as measured by the cleanliness of rings, lands, ring grooves and piston skirts. Cleanliness ratings are based on a scale of from 100 to 0, a 100 rating signifying a perfectly clean condition and a rating representing the worst possible deposit condition.

A single cylinder, 4-cycle, liquid cooled Lauson engine with splash lubrication is used. The operating conditions are as follows:

Oil temperaturv F. 225 laclzet temperature, F 275 Speed, r.p.m. 1,825 Brake load, HP. 1.6 One-half throttle.

l3l air-fuel ratio.

Oil added every 20 hours (one gallon sample used).

Oil temperature, F. 175 Jacket temperature, F 215 Speed, r.p.m. 1,825 Brake load, HP 7.5 Heat input, Btu/min. 1260 Oil addition every 8 hours starting at 4 hours 1 /2 gallon sample used).

The duration of the test is 60 hours. The fuel used is a No. 2 fuel oil containing 1% sulfur. The results are reported in terms of piston cleanliness ratings as in the D-4 test.

THE CATERPILLAR ENGINE TEST This test determines the ability of an oil to prevent piston deposits and top ring wear. A single cylinder, 4- cycle Caterpillar engine is used. The operating conditions are as follows:

Oil temperature, F. 150 Jacket temperature, F. 180 Speed, r.p m 1000 Brake load, HP. 19.8

10 The duration of the test is 120 hours. The amount of piston deposits at the end of the test is expressed in terms of piston cleanliness ratings on a scale from 0 to as in the Lauson D4A and Diesel D-2l tests. The diesel fuel used in the test contains 0.4% sulfur.

THE RADIOACTIVE PISTON RING WEAR TEST This test permits measurement of piston ring wear rate in a relatively short period of time as no dissembly of the engine for inspection and wear measurement is required. Briefly, the procedure is as follows. The rings used are made from a single melt of metal. They are activated to a level of approximately 2.5 millicuries per ring. Iron-55 and iron-59 are the radioactive isotopes produced. Using special tools and equipment to protect against radiation hazards, the rings are installed in the top groove of the piston where the highest pressures, temperatures and wear are encountered. The test engine is a modified A.S.T.M. knock test unit. During the operation or" the engine, the radioactive iron worn from the piston ring is carried by the oil to the radiation detection equipment which is activated by gamma radiation (from iron-59) from ring debris in the circulating oil. The pulses generated are received by a ratemeter and translated to counts per minute (c.p.m.), which in turn are recorded as an integrated graph of c.p.m. vs. time. Wear rates may be converted to absolute wear in milligrams per unit of time. To do this, a Weighed segnent of a piston ring irradiated at the same time as the test ring is first converted to an oil-soluble salt, such as iron naphthenate. An oil blend of this salt is then circulated to the detector to determine the c.p.m. per milligram of iron present. A standard curve for decay of iron-59 is drawn, based on a 46.3 day half-life. By comparing the c.p.m./m for the test oil and the c.p.m. per milligram of iron-59 in the iron naphthenate blend, a value of wear expressed in milligrams of iron per minute can be assigned to the test oil. For purpose of comparison absolute wear rate values are generally converted to milligrams (of iron) per hour.

Table I LAUSON DETERGENCY TEST (3011011., Piston Product (Blended in an S.A.E. 20 Solvent-Refined Wt. Per- Oleanli Pa. Oil) cent ness Rating None 0 60 Example 1 3 74 Table II DIESEL DETERGENCY TEST COHOYL, Piston Product (Blended m an S.A.E. 30 Solvent- Refined Wt. Per- Cleanli- Mid-Gontinent Oil) cent ness Rating None 0 67 Example 6 6.35 92. 3

Table III CATERPILLAR ENGINE TEST Gonen, Piston Product (Blended in an S.A.E. 30 Solvent-Re- Wt. Cleanlifined Mid-Continent Oil Percent ness Rating None 0 61. 9 Example 1 2. 97 98. 2 Example 2. 3. 0 97. 2

It will be observed from Tables I, II and III that the high barium content complex salts of the invention provide excellent detergent action in engine lubricating oils. Also, from the results presented in Table IV, it will be evident that the complex salts are highly effective in preventing piston ring wear and that they are much more effective on a Weight for weight basis than well known basic salts, such as Product A.

EVALUATION OF COMPLEX SALTS AS FUEL ADDITIVES The ability of the high barium content complex salts as fuel additives both for the prevention of oil deterioration With consequent sludge formation in fuel oils in storage and as anti-screen clogging agents in contaminated fuel oils have been demonstrated by means of the following tests.

SIX W'EEKS STORAGE TEST In this test a 500 milliliter sample of the fuel oil under test is placed in a convected oven maintained at 110 F. for a period of six Weeks. The sample is then removed from the oven and cooled. The cooled sample is filtered through a tared asbestos filter (Gooch crucible) to remove the insoluble matter. The weight of such matter, in milligrams, is reported as the amount of sediment. The effectiveness of an additive as a sediment inhibitor is determined by comparing the test data for the inhibited fuel oil with that of the uninhibited fuel oil. The base fuel oil used comprised a blend of 60% catalytically cracked component and 40% straight-run component and had a boiling range of approximately 320 F. to 640 F. The test results are given in Table V.

Table V It will be seen from the test data that the complex barium sulfonate salts effectively stabilize the fuel oil against sludge formation in storage.

ANTI-SCREEN CLOGGING TEST This test is conducted with a Sundstrand V3 or 81 home fuel oil burner pump with a self contained 100 mesh Monel metal screen. About 0.05%, by Weight, of naturally formed fuel oil sediment, composed of fuel oil, Water, dirt, rust and organic sludge is mixed with liters of the fuel oil. This mixture is circulated by the pump through the screen for 6 hours. The sludge deposit on the screen is Washed off with normal pentane and filtered through a Gooch crucible. After drying, the Gooch crucible is washed with a 50-50 acetone-methanol mixture. The total organic sediment is obtained by evaporating the pentane and acetone-methanol filtrates. Drying and weighing the Gooch crucible yields the inorganic sediment. The sum of the organic plus inorganic deposits on the screen may be reported in milligrams or converted to per cent of screen clogging. The base fuel used l2 in these tests was the same as that used in the aforedescribed storage test. The test results are presented in Table VI.

Table VI ANTI-SCREEN CLOGGING TEST Goncn, Screen Product Added lb./l.00tl Clogging, bbls. Percent None 0 10 Example 2-- 50 Example 4" 50 Example 6.- 50

It will be seen from the data in Table VI that the products of the invention are effective anti-screen clogging agents for usein fuel oil.

As indicated hereinbefore, the products as provided by the process of this invention are ordinarily concentrated oil solutions of the 'high barium content complex salts, these solutions containing from about 25% to about 75%, by weight, of the complex salts. The amounts of the products to be added to a lubricating or fuel oil to provide a particular concentration of the complex salt therein is, therefore, apt to vary somewhat from product to product. As a practical matter, however, differences in the products can be readily eliminated by standardization of process conditions and/ or final adjustment of the product oil solution to some standard salt content as will be readily appreciated by those skilled in the art. Allowing for the usual variations in the complex salt contents of the product oil solutions, i.e., from about 25% up to about 75% of the complex salt, the amount of the products to be utilized as detergents in lubricating oils will range broadly from about 0.5% to about 30%, by weight, the usual amount being from about 2% to about 8%. 0n the other hand, when the products are utilized as fuel oil additives, the amounts thereof to be employed will range from about 10 to about 200 pounds per 1000 barrels of fuel oil, i.e., from about 0.003% to about 0.06%, by weight.

The lubricating and fuel oil compositions of the invention may contain other addition agents along with the complex salt products disclosed herein. Thus, for example, lubricating oil compositions may contain pour point depressants, viscosity index improvers, extreme pressure agents, additional deter-gents, etc., while the fuel oils may contain de-emulsifiers, ignition improvers and the like.

Although the present invention has been described herein by means of certain specific embodiments and illustrative examples, it is not intended that the scope thereof be limited in any way thereby but only as indicated in the following claims.

This application is a division of our application Serial No. 664,465, filed June 10, 1957, now Patent No. 3,046,224.

What is claimed is:

l. A method for preparing a high barium content complex salt of a sulfonic acid which comprises the steps of (1) subjecting a hydrocarbon solution of a basic barium salt of a sulfonic acid, selected from the group consisting of .alkaryl sulfonic acids and petroleum sulfonic acids, to treatment with carbon dioxide while maintaining the temperature of said hydrocarbon solution at a level of from about C. to about 250 (3., the amount of carbon dioxide employed during said treatment being at least about 1 mol per mol of basic barium sulfonate salt in said hydrocarbon solution, (2) lowering the temperature of the reaction mixture from step 1 to a level of from about 25 C. to about 60 C., (3) adding barium methylate to the reaction'mixture from step 2 in an amount to provide at least about 1 equivalent of barium per mol of basic barium sulfonate salt employed in step 1, (4) raising the temperature of the reaction mixture to a level of 13 about 150 C. to about 250 C. and filtering the re action mixture to recover a hydrocarbon solution of the high barium content complex salt of sulfonic acid.

2. The method defined in claim 1, but wherein the reaction mixture from step 4 is subjected to further treatment with carbon dioxide and barium methylate to in corporate additional carbon dioxide and barium into the complex salt product.

3. A method for preparing a barium content complex salt of a wax-benzene sulfonic acid which comprises the steps of (l) subjecting an oil solution of a basic barium salt of the wax-benzene sulfonic acid to treatment with carbon dioxide while maintaining the temperature of said hydrocarbon solution at a level of from about 150 C. to about 250 C., the amount of carbon dioxide employed during said treatment being at least about 1 mol per mol of basic barium salt in said hydrocarbon solution, (2) lowering the temperature of the reaction mixture from step 1 to a level of from about 25 C. to about 60 C., (3) adding barium methylate to the reaction mixture in an amount to provide about 1 equivalent of barium per mol of the basic barium sait of Wax-benzene sulfonic acid employed in step 1, (4) raising the temperature of the reaction mixture to a level of from about 150 C. to about 250 C. and (5) filtering the reaction mixture to recover an oil solution of the high bariurn content complex salt of the wax-benzene sulfonic acid.

4. The method defined in claim 3, but wherein the reaction mixture from step 4 is subjected to further treatment with carbon dioxide and barium methylate to incorporate additional carbon dioxide and barium into the complex salt product.

5. A method for preparing a high barium content complex salt of a Wax-naphthalene sulfonic acid which comprises the steps of 1) subjectin an oil solution of a basic barium salt of the Wax-naphthalene sulfonic acid to treatment with carbon dioxide while maintaining the temperature or" said hydrocarbon solution at a level of from about 150 C. to about 250 C., the amount of carbon dioxide employed during said treatment being at least about 1 mol per mol of basic barium salt in said hydrocarbon solution, (2) lowering the temperature of the re action mixture from step 1 to a level of from about 25 C. to about 60 C., (3) adding barium methylate to the reaction mixture in an amount to provide about 1 equivl4 talent of barium per mol of said basic barium salt of waxnaphthalene sulfonic acid employed in step 1, (4) raising the temperature of the reaction mixture to a level of from about 150 C. to about 250 C. and (5) filtering the reaction mixture to recover an oil solution of the high barium content complex salt of the wax-naphthalene sulfonic acid.

6. The method defined in claim 5, but wherein the reaction mixture from step 4 is subjected to further treatment with carbon dioxide and barium methylate to incorporate additional carbon dioxide and barium into the complex salt product.

7. A method for preparing a high barium content complex salt of a petroleum sulfonic acid which comprises the steps of (1) subjecting an oil solution of a basic barium salt of a petroleum sulfonic acid to treatment with carbon dioxide, while maintaining the temperature of said oil solution at -a level of from about 150 C. to about 250 C., the amount of carbon dioxide employed during said treatment being at least about 1 mol per mol of basic barium sulfonic acid salt in saidhydrocarbon solution, (2) lowering the temperature of the reaction mixture from step 1 to a level of from about 25 C. to about (3., (3) adding barium methylate to the reaction mixture in an amount to provide about 1 equivalent of barium per mol of the basic barium salt of the petroleum sulfom'c acid employed in step 1, (4) raising the temperature of the reaction mixture to a level of from about C. to about 250 C. and (5) filtering the reaction mixture to recover an oil solution of the high barium content complex salt of the petroleum sulfonic acid.

8. The method defined in claim 7, but wherein the reaction mixture from step 4 is subjected to further treatment with carbon dioxide and barium methylate to incorporate additional carbon dioxide and barium into the complex salt product.

References Cited in the file of this patent UNITED STATES PATENTS 2,413,311 Cohen Dec. 31, 1946 2,695,910 Asself et a1. Nov. 30, 1954 2,856,360 Schlicht Oct. 14, 1958 2,881,206 Kjonass et :al. Apr. 7, 1959 2,924,617 Wright Feb. 9, 1960 

1. A METHOD FOR PREPARING A HIGH BARIUM CONTENT COMPLEX SALT OF A SULFONIC ACID WHICH COMPRISES THE STEPS OF (1) SUBJECTING A HYDROCARBON SOLUTION OF A BASIC BARIUM SALT OF A SULFONIC ACID, SELECTED FROM THE GROUP CONSISTING OF ALKARYL SULFONIC ACIDS AND PETROLEUM SULFONIC ACIDS, TO TREATMENT WITH CARBON DIOXIDE WHILE MAINTAINING THE TEMPERATURE OF SAID HYDROCARBON SOLUTION AT A LEVEL OF FROM ABOUT 150*C. TO ABOUT 250*C., THE AMOUNT OF CARBON DIOXIDE EMPLOYED DURING SAID TREATMENT BEING AT LEAST ABOUT 1 MOL PER MOL OF BASIC BARIUM SULFONATE SALT IN SAID HYDROCARBON SOLUTION, (2) LOWERING THE TEMPERATURE OF THE REACTION MIXTURE FROM STEP 1 TO A LEVEL OF FROM ABOUT 25*C. TO ABOUT 60*C., (3) ADDING BARIUM METHYLATE TO THE REACTION MIXTURE FROM STEP 2 IN AN AMOUNT TO PROVIDE AT LEAST ABOUT 1 EQUIVALENT OF BARIUM PER MOL OF BASIC BARIUM SULFONATE SALT EMPLOYED IN STEP 1, (4) RAISING THE TEMPERATURE OF THE REACTION MIXTURE TO A LEVEL OF ABOUT 150*C. TO ABOUT 250*C. AND (5) FILTERING THE REACTION MIXTURE TO RECOVER A HYDROCARBON SOLUTION OF THE HIGH BARIUM CONTENT COMPLEX SALT OF SULFONIC ACID. 